Topping up boiler, how often?

[dilalio]

It's better to isolate the boiler yourself and watch the pressure, because you can do this over a couple of days.

Vaillant chap won't have that time.

 

[wedge69]

Alright, happy to hear people's thoughts on this now. I did not isolate the boiler, instead we just stopped using it from Monday morning, so no heating or hot water.

All these readings are from the digital readout

Fri after service 1.3
Fri pm 1.2
Sat am 1.0
Bled rads 0.9
Topped up 1.3
Sat pm 1.2
Sun am 1.0
Topped up 1.3
Sun pm 1.2
Mon am 1.0
Mon pm 0.9
Tue am 0.9
Tue pm 0.9
Wed am 1.0

So as you can see when I stopped topping it up and stopped using it, there's not been much change over 48 hours, and it even claims to have gone up today.

 

[dilalio]

As I said.... Attach an external gauge.
Possible that boiler pressure sensor is faulty and this would be a way of testing that.

 

[dilalio]

Are there any obvious tell take signs of a leak under the floor? To the best of my knowledge it's screed with tiles on top. There's no visible signs of dampness

I've also just double checked all radiators and they're dry

You could add some TCP or dettol to the system and see if you can smell out a leak!

 

[dilalio]

So as you can see when I stopped topping it up and stopped using it, there's not been much change over 48 hours, and it even claims to have gone up today.

There are "hot" leaks and "cold" leaks.
Pump pressure also is a factor with a running boiler, as is thermal expansion when running DHW only.

 

[wedge69]

I've not had the central heating on at all yet (apart from the half hour during the service). I don't really want to start messing with anything until the fella has been tomorrow, just thought it would be useful to start recording the pressures.

Knowing me, there won't be anything wrong and it will just have been the boiler settling down after the service, though to me topping it up that much isn't normal.

 

[Notch7]

I had a new boiler on an existing central heating circuit in Jan

I’ve topped up the pressure twice in that time.

 

[Mottie]

What happens if you don’t top it up?

 

[wedge69]

What happens if you don’t top it up?

You can see from above. It dropped to 0.9 and has stayed there for 48 hours

 

[dilalio]

What vaillant is it?
A pure will work down to 0.5 (as indicated by the range it asks you to pressurise it to).

 

[wedge69]

What vaillant is it?
A pure will work down to 0.5 (as indicated by the range it asks you to pressurise it to).

EcoFIT pure

 

[dilalio]

EcoFIT pure

I went to one yesterday.
Opposite problem... Filling loop was defective and was letting by.
System was over pressurising.
Vaillant wanted @£180 for a new loop so I capped it off and installed a separate 3rd party one below boiler.

£180 FFS for 2 valves and a flexi!

 

[Harry Bloomfield]

Alright, happy to hear people's thoughts on this now. I did not isolate the boiler, instead we just stopped using it from Monday morning, so no heating or hot water.

All these readings are from the digital readout

Ambient temperatures can also affect the pressure, the digital readout shows. That might explain your increasing pressures. What matters, is the general trend.

 

[wedge69]

Ambient temperatures can also affect the pressure, the digital readout shows. That might explain your increasing pressures. What matters, is the general trend.

The general trend was three consecutive daily drops from 1.3 to 1.0 when only using the water, followed by holding steady at 0.9/1.0 for 3 days when not in use at all, so who knows.

 

[Mottie]

You might be worrying unnecessarily. Why not top it up near to the recommended maximum pressure and see how long it takes to get to the minimum pressure to keep working? It might take a year to get there. Nothing to lose and you won’t damage anything.